Do you like to read detective stories or watch them on TV? What makes them exciting for you and me is the suspense. We want to find out who did it, or how, or why. But the world around us is full of mysteries, too.

Why do animals behave as they do? What makes plants grow in special ways? How does our body do this or that?

Man has always wanted to solve these mysteries of life. And just the way a detective proceeds on a case, the first thing that had to be done was to gather all the facts. The gathering and the study of these facts was called natural history.

Today we calf this science biology. The word comes from two Greek words: bios, meaning “life,” and logos, meaning “a study.” So biology is the study of all organisms, plant and animal. What is studied about them is their form, their activities, their functions, and their environment.

But today our biologist-detectives are not satisfied just to collect a lot of facts, helter-skelter. They try to establish some links between the facts, some relationship. For example, they are interested in discovering the relationships that exist between man and the millions of living things that surround him. They want to know what effect these living things have had on man’s own development.

Biologists are interested in the greatest mystery of all: how life first started on earth and why it took the forms it did. So they also study all the conditions that are necessary to life. And just as a detective bureau keeps a file, they try to classify every organism which exists on our planet.

In looking for clues that will answer their questions, biologists get a helping hand from nature. They dredge the icy depths of the oceans and scale the peaks of the tallest mountains looking for clues. They hack their way through steaming jungles, and peer for hours into microscopes. Sometimes they perform strange experiments in order to get at the mystery of life.

Biology is a very complex science. It has two main divisions: botany, which deals with plants; and zoology, which deals with animals. And each of these divisions is separated into dozens of subdivisions!